[pseudoanonym]

I have a meta42 which has been completed for some time, and I currently have 4x 470uF (25v) caps in C2/C3 (2 per rail).

I like this amp, but I've never been overly happy with the bass response. Is there any value to putting larger caps in C2/C3, and is it possible to have too much capacitance here.

The reason I ask is that I have a couple of 3300uF caps I took out of an old power supply which would fit (they are quite high, but not very large in diameter.

Am I insane for wanting to put these generic caps in there, and/or is 3300uF per rail too much?

 

[peranders]

Yes, a little.

The amp is very powerfull compared to the load and the total amount of capacitance is sufficient for a smaller power amp. If you are lacking bass, can it be your phones? Reproducing bass is an easy task the amp. You could also be used to an amp or a signal source with not so good treble (= more bass?)

 

[pseudoanonym]

For what it's worth I'm using Sennheiser HD-580's with this amp.

 

[MegaMeee]

i am also wondering about caps - probably going with panasonic fc or fa series caps - dont know what else i can get from rs.

dont know if going higher voltage is an improvement and if higher capacitance is a significant improvement.
i could get 2200 or 3300uf 16v caps, or i could buy 1000uf 35v. they are all 12.5mm diameter and should all fit in my *case* (i use the term loosely - more details when i finish it). the 3300uf cap has .8mm diameter wires - not sure if it will fit on the board. dont know if it really matter which ones i get.

 

[Ambush]

There was a thread about this somewhere; one person stated that more than 1000uF per channel (ie 2x470uF) was overkill. What C1's did you use, pseudoanonym?

 

[KTpG]

My current amp (not exactly a META42, but the same topology and basic circuit) uses about 32,170.1uF per rail. Sounds great... no problems with 'too much.' I ovderdo caps anyway, I like their looks, and really don't think having too much can hurt anything anyway. My upcoming amp will use regulated power supplies with approximately 67,000uF per rail. If anything MAYBE bass was a tad more defined? I don't know. My subconcious might have been trying to justify the huge caps in the PS.

Just my .02 on caps...

 

[RockysDad]

Quote:

What C1's did you use, pseudoanonym?

Ambush might be on to something... For a better bass response, try swapping C1 with a larger value or even removing it completely (you might want to test your source for DC at the output first, though). This gave me a ton more bass in my META clone amp.

As far as the bypass caps, you seem to have enough.

Just my $.02...

 

[10SNE1]

Tweaking C1 is more likely to produce audible results as it is essentially part of a high-pass filter whose purpose is to block low frequency (including DC) signals. The low-freq cutoff which is germane to low frequency performance is inversely proportional to the value of C1; i.e., as the value of C1 increases, the low frequency cutoff drops and more low-freq signal, so to speak, is passed on to the input of the amplifier.

Tangent discusses this in his META42 tweaks section.

Note that the Grado RA-1 uses a rather large value for the equivalent capacitor - 5 uf - in that circuit.

Augmenting C2/C3 won't be useful beyond what you already have.

 

[puppyslugg]

Quote:

Originally posted by KTpG My current amp (not exactly a META42, but the same topology and basic circuit) uses about 32,170.1uF per rail. Sounds great... no problems with 'too much.' I ovderdo caps anyway, I like their looks, and really don't think having too much can hurt anything anyway. My upcoming amp will use regulated power supplies with approximately 67,000uF per rail. If anything MAYBE bass was a tad more defined? I don't know. My subconcious might have been trying to justify the huge caps in the PS. Just my .02 on caps...

KTpG:

I like your style!!

If you really like big caps check these out:

http://www.powerstor.com/products_supercapacitors.asp

Run a few in series for voltage and you'll make monster power amps blush!!

 

[Squalish]

Quote:

Originally posted by puppyslugg KTpG: I like your style!! If you really like big caps check these out: http://www.powerstor.com/products_supercapacitors.asp Run a few in series for voltage and you'll make monster power amps blush!!

Supercaps have relatively limited lifespans, in the hundreds of thousands of charge cycles rather than virtually unlimited.

I don't know about equivelant measurable audio usage, but I suspect that they won't last long compared to normal caps.

 

[puppyslugg]

Quote:

Originally posted by Squalish Supercaps have relatively limited lifespans, in the hundreds of thousands of charge cycles rather than virtually unlimited. I don't know about equivelant measurable audio usage, but I suspect that they won't last long compared to normal caps.

I'll find out soon enough.

Here's someone who has used the Supercaps in audio apps:

http://www.audioasylum.com/audio/twe...ges/83561.html

 

[zbuddah]

Going from 1000uf (4000uf total) sprague each cap to 220uf (880uf total) cerafines each cap I noticed a loss of punch in the bass but gained in a cleaner sort of sound. Differences were not mind boggling major for me so...

try teh C1 route, if your still not happy switch opamps to the AD843 i have not heard these personally but they are on my list of "to get" things, it is suppose to have great bass at a sacrafice.

 

[pseudoanonym]

Thanks for the advice. I'll try tweaking C1 and see if that makes a difference.